The Special Area of Conservation (SAC) of Ponta do Castelo - Santa Maria island (PTSMA0022) is one of the most important geological landscapes of Santa Maria island, located in the Azores. This site contains rare vegetation with Atlantic-Mediterranean characteristics, and harbours several endemic species as well as many species protected under the Habitats Directive. This site is also important for birds (according to BirdLife International criteria) and the surrounding marine area is a major crossing point for the bottlenose dolphin (Tursiops truncatus) and the loggerhead turtle (Caretta caretta).The SAC also protects several habitats of community interest (1160,1210,1220,1250 and 8330) and a large number of species of regional and international importance, including 5 plant species protected under Habitats Directive (Azorina vidalii*, Erica azorica, Lotus azoricus*, Picconia azorica and Spergularia azorica) and 6 bird species protected under Birds Directive.The main threat comes the presence of Invasive Alien Species, namely the Agave americana, Carpobrotus edulis and Spinacia oleracea. Together they threaten one of the most important populations of Lotus azoricus in the Azores (a species evaluated as having an unfavourable status in the last report). Taking into account the main pressures and importance of this Site, a Nature Custody Agreement was established whose key objectives are to: i) control of IAS; ii) restore habitats for the conservation of the populations of Lotus azoricus, Azorina vidalii and Spergular azorica and iii) promote nature conservation for volunteer tourism.